Use this free online calorie calculator to estimate daily calorie needs from resting metabolism and activity level. Enter sex, age, weight, height, and activity. The tool multiplies Mifflin St Jeor BMR by your activity factor to estimate maintenance calories. No signup is required.
Daily needs differ from basal metabolic rate alone. BMR is the energy estimate at rest. This calorie calculator scales BMR by activity so you can plan intake for maintenance. It is an educational estimate, not a personal medical meal plan.
See also the BMR calculator, BMI calculator, body fat calculator, and pace calculator in nutrition and health calculators.
What the result means
The primary result is estimated calories per day to maintain current weight at the selected activity factor. Eating consistently above that estimate tends to support weight gain over time. Eating below it tends to support a deficit. Individual responses vary with health status, medications, and measurement error.
How to use the calculator
- Select sex.
- Enter age in years.
- Enter weight in kilograms and height in centimeters as the form requests.
- Choose an activity factor that matches your typical week.
- Read the daily calorie estimate.
How the calculation works
Male BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5
Female BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161
Daily calories ≈ round(BMR × activity factor)
The default activity factor in the interface is often 1.55 for moderate activity when unchanged. Higher factors raise the daily estimate. This matches the Multicalify implementation.
| Example input | Value |
|---|---|
| Sex | Female |
| Age | 30 |
| Weight | 65 kg |
| Height | 165 cm |
| Activity factor | 1.55 |
BMR ≈ 10×65 + 6.25×165 − 5×30 − 161 = 650 + 1031.25 − 150 − 161 = 1370.25. Daily ≈ round(1370.25 × 1.55) = 2124 kcal/day.
Choosing an activity factor
Be honest about weekly movement. Office work with light walks is not the same as hard training six days a week. If weight trends up while you eat near the estimate, the activity factor may be too high or portions may be undercounted.
Calorie calculator versus BMR calculator
Use BMR when you only need resting burn. Use this calorie page when you need a daily target that includes activity. Keeping those intents separate reduces keyword overlap and helps readers land on the right tool.
Common mistakes
- Selecting an optimistic activity level
- Entering pounds into a kilogram field
- Treating the estimate as a fixed medical prescription
- Changing intake drastically overnight without a plan for protein, sleep, and strength work
Limitations
Equations estimate averages. Pregnancy, illness, and clinical conditions need professional guidance. Multicalify does not diagnose or treat any condition.
Conclusion
A clear calorie calculator estimate gives you a maintenance starting point. Confirm inputs, pick a realistic activity factor, then adjust using weekly averages rather than a single day on the scale.
Using the estimate for a gentle deficit or surplus
If your goal is weight loss, many people start with a modest reduction from maintenance and track a multi week average. Aggressive cuts can backfire through fatigue and adherence problems. If your goal is gain, a small surplus paired with progressive training is often easier to manage than a huge jump in intake.
Revisit the calculator when weight, age, or routine changes. Pair composition context from the body fat and BMI tools instead of judging progress by scale weight alone.